Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
920 FXUS66 KSTO 112119 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 219 PM PDT Sun Aug 11 2024 .SYNOPSIS... Cooler temperatures and increasing humidity, with periods of breezy onshore winds this week. && .Discussion... Current GOES-West visible satellite imagery shows mostly sunny skies across interior northern California with the exception of some passing mid to high level clouds on this Sunday afternoon. For much of interior NorCal, current temperature observations are trending approximately 2 to 5 degrees cooler than this time yesterday afternoon, valid at 215 PM PDT. The Delta area is observing a more noticeable temperature difference, around 12 degrees cooler than 24 hours ago at Fairfield/Travis AFB. High pressure will weaken across the region as the influence of upper level troughing increases. As a result, a cooling trend with increasing humidity and periods of breezy onshore flow are in the forecast over the next few days. A shortwave trough moving across the area on Monday will bring increased onshore flow, and chances for sprinkles or light precipitation, mainly to the higher elevations of the northern mountains. Increased clouds may be observed elsewhere on Monday but otherwise, dry conditions continue. Temperatures on Monday and Tuesday will generally be in the 80s to low 90s in the Valley and foothills, with 60s to mid 80s in the mountains, and mainly Minor HeatRisk. Slightly warmer temperatures are expected Wednesday in between shortwaves with slightly higher heights, however conditions are forecast to remain near or below the climatological normal this week. && .EXTENDED DISCUSSION (Thursday THROUGH Sunday)... Ensemble guidance and cluster analysis indicate that the influence of upper level troughing will continue over the extended forecast period. A shortwave moves across NorCal on Thursday and then a low pressure area deepens later in the week and over the weekend. Increased humidity, and cooler than climatological normal temperatures are expected as a result of this pattern. High temperatures are expected to generally be in the 80s to low 90s in the Valley and 60s to mid 80s for the foothills and mountains over this timeframe, with mainly Minor HeatRisk each day. Periods of breezy onshore winds are forecast, primarily through the Delta area and over the Sierra Nevada. && .AVIATION... VFR conditions over interior NorCal next 24 hrs except isolated MVFR in HZ/FU possible at times in vcnty of fires. Southwesterly winds 10-15 kts with gusts 15-20 kts between 21z-10z otherwise wind below 12 kts. In and around the Delta, southwesterly surface winds sustained 15-20 kts with gusts 20-30 kts at times. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$